Photo-electric tube



Jan. 2, 1934. H. H. GEFFCKEN ET ALl 1,942,165

PHOTO ELECTRI C TUBE Filed July 29, 1929 Patented Jan. 2, 1934 UNITE STTES PHIO-ELECTRC TUBE Heinrich H. Geffcken and Hans R. Richter, Leipzig, Germany Application July 29, 1929, Serial No. 381,727, and in Germany August 6, 1928 4 Claims.

The present invention, generally stated, relates to photo-electric tubes, and is particularly concerned with improvements aiming to increase the reliability of operation of such a tube.

It is well known that the photo-electric tube is widely used for a variety of technical purposes, e. g., in various kinds of relay arrangements, and particularly in apparatus for the transmission of pictures and apparatus for talking films. In

the latter case, the photo-electric currents must be amplified and this amplication must reproduce clearly and distinctly the iinest shades of the production.

It was found that small mechanical oscillations 5 of the anode, such as may occur as a result of the shaking of the apparatus, manifest themselves frequently to a disagreeable degree when the photoelectric currents are greatly amplied.

F These mechanical oscillations cause periodic al- 40 terations of the tube capacity, which appear as shades or stripes on the received picture, in ease of picture transmission, and in form of humming or singing sounds, in case of the talking nlm.

The present invention avoids these disadvantages. The invention consists, principally, in providing additional support for the anode which is usually fastened rod like in the tube. This additional support is preferably provided on a point farthest removed from the usual support of the anode, that is to say, iarthest removed iroin the place where the conductors are fastened in. the glass body of the tube. The additional support may be provided either by a fastening on the tube Wall, e. g., in the end point of the body, or attaching a glass rod, or a glass tube to the foot which serves for carrying the conductors, which reaches into the tube body and holds the anode at the end which is to be supported in accordance with this invention. The form of carrying out the invention which was rst mentioned furnished better protection against breakage, and the second renders the most favorable insulation conditions, so that the one may be chosen which is most advantageous in accordance with prevailing conditions. However, either of the provisions makes mechanical oscillations of the anode practically impossible, or rather, keeps such oscillations within such narrow limits, as to reduce the alterations of capacity connected therewith, to a negligible amount.

The invention will be better understood' from a detailed description, which will now be presented with reference to an accompanying single sheet of drawing, showing two forms of applying the invention to practical use.

In the drawing, Fig. 1 is a schematic view of one form of my invention and Fig. 2 is a schematic view of a modified form of my invention.

Referring now to Fig. 1 of the drawing, in the G0 tube body designated by numeral l, which may be covered with a photo-electric layer, are the conductors 2 of the anode 3 shown as entering thru the stem 4. The anode may have the form of a loop, as shown, or a spiral, or net form, etc. In accordance with the invention, the anode is supported or held a second time opposite the place where the conductors enter the tube thru the stem 4. The supporting rod 6 serves this purpose. It may be attached to the anode at point 5 by means of spot welding, or by means of any other suitable attachment. The fastening of the supporting rod 6 to the wall of the tube body may be accomplished by simple melting into the end point at 7, or, as is illustrated in the drawing, by elastically catching the supporting rod at its looped end, within the end point 7.

Fig. 2 shows another form of carrying out the invention. In this case, a glass rod or arm 8 is attached to both sides of the part of the stem 4, These arms reach into the tube and hold the anode at points 9, thus providing a suitable additional support and preventing oscillations detrimental to the perfect operation of the tube.

What is claimed is:

1.` A photo-electric tube having a cathode and a looped anode supported at one end, and means supporting anode at a second point within the tube and directly on the wall of the tube, the point of said second support being located opposite .said first support.

2. Aphoto-electric tube having a cathode and a looped anode supported at one end, means attached to said anode opposite said iirst support additionally supporting said anode ,to prevent its oscillations, and means on said first means for .securing the same directly in the end point or" said tube, thereby fastening said anode.

3. A photo-electric tube having a cathode and a looped electrode, a rst support therefor at one end, means attached to said electrode opposite said first support providing a further support for said electrode to prevent its oscillation, and flexible means secured to a wall of .said tube and supporting said last mentioned means.

Ll. A photo-electric tube comprising a sealed envelope; a laterally extending stem therein; an anode electrode consisting of a looped rigid wire; a lead-in wire extending through said stem and connected to said anode electrode and supporting said anode electrode; a light sensitive cathode electrode; and a second support within said tube rigidly supporting said anode electrode, said second support being secured to said anode electrode at a point opposite to said rst-mentioned support.

HEINRICH H. GEFFCKEN. HANS R. RICHTER. 

